Specific IgG antibodies (total and subclasses) against Saffron pollen: a study of their correlation with specific IgE and immediate skin reactions.

Saffron (Zaaferan), botanical name Crocus sativus, is the most expensive spice in the world. It is derived from the dried stigma and pistil of the purple saffron crocus flowers. Iran is the largest saffron producer accounting for more than 80% of the world's production. Saffron contains an aeroallergen that causes reactive respiratory allergic reactions in atopic subjects. IgG antibody to allergens in the serum of allergic patients is not routinely measured. In this study in order to find out more about mechanism of allergy against saffron pollen, specific antibodies (IgE and IgG, total and subclasses) in atopic subjects were assayed. We used an ELISA assay for measuring specific IgE and IgG against saffron pollen extract in the sera of 38 atopic subjects (test group) and 20 non allergic subjects (control group). The optical densities were compared between allergic subjects and non-allergic individuals. The prick test with saffron pollen extract was used to evaluate the cutaneous and specific antibody responses in the allergic subjects. The correlation was determined by statistical analysis. Specific saffron pollen IgE and IgG subclasses were found significantly higher in the allergic subjects than the control group. The immediate skin reaction was found positive in 70% of the test group. We report here, the existence of a positive correlation between specific IgE and skin reaction by prick test in atopic subjects (R= 0.433). A negative correlation between specific IgE and IgG4 subclass was also found (R= -0.576). These data may be useful to understand the mechanism of allergy to saffron and may help in clarifying clinical manifestations and to prevent IgE production as well as therapeutic application.